Tubular wall structure



1928 2 Sheets-Sheet, 1

E. H. TENNEY TUBULAR WALL STRUCTURE Filed June 28. Z 0 .1.

Nov. 1, 1932.

INVENTOR.

FNMA {W aww ATTORNEYS.

lfli s a ||T ll m lmimil I a 22m lwi 111 Hun Nov. 1,1932, E, H, TENNEY 1,886,314

TUBULAR WALL STRUCTURE Filed June 26, 1928 2 Sheets-Sheet 2 66 I Er I E I HTTORNL' vs.

Patented Nov. 1, 1932 NITED SATS 'rUia LAn WALL srnucrunn Application filed June 26,

This invention is a novel tubular wall structure. Its particular utility as herein dis. closed and designed is for any of the walls, including side, bottom, or other walls, of a 5 furnace, particularly a boiler furnace; al-

though the invention may be useful in connection with other walls where circulation tubes are embodied in the walls and require protecting coverings of high heat transmitting qualities.

Among the objects of the present invent on are to afford a wall containing circulation tubes, and a covering structure for such walls, which will be simple, inexpensive and strong of structure, and effective in action both as regards the protection of the tubes agamst very high temperatures and as. regards the transfer of heat to the medium circulating in the tubes. A further object of the invention is to provide a metallic wall covering of the kind referred to which will be exceedingly free from deterioration, and possessing a. long life notwithstanding high temperatures and extremevariations of temperature} A further object is to provide a wall covering structure, particularly in the form of lron covering members or blocks, in which the covering elements are readily removable and individually replaceable when necessary.

I Other and further objects and advantages of the present invention will be explained in the hereinafter following description of an illustrative embodiment thereof or will be understood to those skilled in the subject thereof- To the attainment of the objects and advantages referred to the present invention consists in the novel wall structure or metal covering for tubular walls, and the novel features of combination, arrangement and structure herein illustrated or described.

In the accompanying drawings Fig. 1 is a transverse section of a wall structure embodying the present invention, in which the tubes may be considered as upright boiler tubes.

Fig. 2 is a rear or outside elevation of the wall shown in Fig. 1. In each of Figs. 1 and 2 is shown only a portion of a wall, indicating the principle of structure, which may 1928. Serial noirasaassi be 'extended indefinitely to a wall of any length or breadth. Fig. 3 is a View similar to Fig. l showingv a modified structure. v

Fig. 4 is a view similar to Figure 2 of a portion of a wall embodying the invention. in a further modified form. f

Fig. 5 is a view similar to Fig-1 showing a modified structural arrangement at the back of. the wall. 1-1 I I,

Fig. 6 is a right hand viewoflthe parts shown in Fig. 5. I Fig. 7 shows another modification of the. rear structure. V Fig. 8 is a rear face view of the structure of In the preferred form, shown in Figs. 1; and 2, are a system of circulationtubes in the: form of ordinary wrought steel'boiler tubes 5, arranged for example in parallel vertical, series and suitablyspaced according to usual practice. In order to protect-the tubes, and to close the spaces between the-tubes and thus provide a substantially continuous water wall or the like,and at the same time provide for the effective transfer of heat through the face or inner side of the wall, so that the wall may be employed to enclose the combustion space of a furnace or otherwise to face fire or ex treme heat, the inventioncomprises-a series of facingmembers or metal blocks 6 assem bled in regular relation to eachother. and in contact with the inner sides of the tubes, Each metal or iron block 6 is shown as having a concave interior or back contour 7 adapted. to fit snugly against the tube 5'; and it is preferred that each facing member or block straddles a tube, with a rearward extension or wing 8 at each side of the tube, sothat the I gaps or spaces which are necessarily'left between each two blocks will fall between two tubes and therefore not tend to expose the tubes themselves to the heat. The slight gaps which appear between each two facing blocks are preferably closed by stufling withan asbestos or other resistant material.

With this advantageous form and arrangement of metal facing blocks the present inven-' tion combines a series of backing members or bars 9 extending transversely to the length of 79 the tubes at the rear or outer sides thereof, along with clamping means extending between the tubes and attaching together the several facing blocks and backing bars. Each backing bar or strip 9 is shown as formed with recesses or perforations 10 to receive the connecting means or bolts 11 by which the structure is tightly assembled and clamped in position.

The clamping connectors or bolts 11 which extend through the wall at both sides of each tube, for holding tightly to the tube the facing blocks 6, are each formed with a bolt head at one end and a thread engaging nut at the other end, one or the other of these ends, preferably the nut, being embedded in the cast metal block 6, while the other end is exterior to the backing bar 9. Thus in Figs. 1 and 2 each connector or bolt 11 is shown as having an outer head 12 back of the backing bar 9, with a washer 13 between the head and the bar, the recesses 10 in the barbein g suiiicicntly larger than the bolts to give convenient leeway for adjustment in interconnecting the parts. The other or threaded end 14 of each bolt is shown engaged in the'threads of a nut 15embedded or cast in the body of the iron block 6. Each of these nuts will preferably be composed of wrought steel and embedded in the cast iron of the block during the casting thereof, with a suitable core to provide a clearance 16 between the metal of the block and the extremity of the bolt, and a circular clearance 17 around the shank of the belt which is subsequently to be engaged in the nut. The bolts 11 at the two sides of each tube 5 are shown spaced slightly from the tubes so as to allow a slight clearance for possible variations in dimensions.

This mode of connecting the blocks and backing bars by bolts, with one end of each bolt embedded in a block, may be varied as shown in Fig. 3 where the bolt 21 has its head 22 embedded in the block 6 while the threaded end 24 of the bolt extends through the backing bar 9 to a rear point where it is engaged by a washer 23 and a nut 25; this being in other words a substantial reversal of the plan disclosed in Figs. 1 and 2. The formerarrangement however is preferable, as the nut is more easily applied during the casting and the completed facing member or block is more compact, occupies less space for shipping, and is less subject to damage.

In either case, when the clamping bolts are tightened into place the backing bars and rigid alinement of the wall tubes tends to preserve a more accurate alinement and flatness to the wall face exposed to the fire. A convenient arrangement is to have each backing bar only several feet long, to cover only several tubes, for example ten, the several bars staggered with relation to each other, thus to rigidify all parts of the wall.

While Fig. 2 indicates only a single continuous backing bar 9 for each horizontal tler of facing blocks 6 it may sometimes be desirable toeflect a more extensive and forcible clamping pressure and for such purpose the arrangement may be adopted as shown in Fig. 4 wherein, instead of the single bar 9 behindeach row of'blocksis shown a double row, or two bars 19, so that the bolts or connectors 11 will be applied proximate to each of the four corners of each facing block, thus securing to a greater degree'each of the advantages already referred to.

In addition to having asbestos packing between individual facingjblocksthe same material may of course be applied behind the blocks and in a manner to fill substantially completely the spaces between the blocks, the tubes and the packing bars, which latter may be supplemented by plates parallel to the tubes and confining the packing material.

To secure more intimate conducting contactbetween the blocks 6 and the tubes 5 there maybe applied any kind of metallic cement, such. as smooth-on, pasted upon the concave surface 7 of the block before application to the tube, this surface being cast:

on a radius slightly larger thanthat of the tube to allow for. the cement.

The bolt andnut employed as a connector provement that the facing lblocksfiare pref-.

erably composed of a particular cast iron, known as white cast iron, which is highly advantageous for the purposes hereof. This material is extremely hard and. not readily machinable but superior as aheat resistant covering. A great advantage in the use of a white cast iron covering block is in its high power to resistv oxidization and flaking even with extremely high temperatures and rapid variations of temperature, thus overcoming one of the notableobjections to ordinary iron or steel covering block s. Additionally, the white cast iron block possesses a smallcoeiiicient of expansion so that there is a minimum amount of expansion and contraction during changes of temperature and corresponding v than materials heretofore tried.

' a ing bar.

An illustrative suitable analysis for the facing blocks of this invention is as follows:

Per cen (1 Carbon 2.960 Silicon -1 1.280 Sulphur .178 Manganese .340 Phosphorous .660 Iron by subtraction 94.582

While the drawings show the invention applied to a plane face wall it is adapted to use on wall of irregular or curved surface. For example, where the boiler tubes in a furnace wall are shaped or curved at any point to conform to the combustion chamber the facing blocks may be cast of corresponding shape or curvature, with the standard bolts or nuts embedded therein as before, these readily cooperating with backing bars the same as described, which in the same manner tends to preserve and rigidify the shape of the wall at the curved location.

In the structure shown in Figs. 5 and 6 there is interposed between each backing bar 29 and each circulation tube 5 an adapting or filling block 34 having a concave inner side 35 to fit the tube and an outer or upper flange or boss 36 contacting and overlying the back- This gives a firmer and more effective clamping contact against the back sides of the tubes and prevents any tendency to distortion of the tubes under the clamping pressure as might sometimes be the case with a tangential contact as in Fig. 1. By having only one flange 36 the filler slips easily into place and the flange, overlying the bar 29, holds the filler in position pending the tightening up of the bolts. The filler 84: may be cast of white cast iron and requires no machining and is therefore inexpensive.

he bolt heads and nuts throughout have been shown as hexagonal, but for cheapness may be of the square type.

The modification shown in Figs. 7 and 8 is one wherein the filler of Figs. 5 and 6 is enlarged into an individual yoke'37 having a concave inner surface or seat 38 contacting the tube 5 and end recesses 39 to receive the bolts 11, in this case the heads 12 of the bolts clamping directly against the individual yoke blocks 37 lVhile this backing structure does not have the advantage of rigidifying the wall and preserving the alinement of the tubes it is useful in certain special situations where the relation of the tubes requires special arrangements for the application of the facing blocks and for clamping into position.

A difi'erent application of the invention is for an air circulation wall, such as an aircooled floor for a furnace burning pulverized or other flowing fuel; in which use the air circulation through thetubes not merely cools the wall structure, but highly preheats the air for combustion purposes. Lighter weight tubes can be used than for water circulation under boiler pressure, the term water including steam. An advantageous air circulation wall structure comprises the tubes, the

facing blocks, the clamping means, and a steel sheet laid between the backing bars 9 and the tubes or fillers. vides additional air passages around or between the tubes and allowsfor thorough air cooling and preheating. Another modifica tion is the circulation of water'through the tubes and air around the tubes. The facing members or blocks may in any case carry embedded refractory facings or inserts, of

This structure pro special use for side walls or arches of stoker except so far as set forth in the appended claims.

What is claimed is 1. A furnace wall structure comprising a system of spaced circulation tubes, a series of facing blocks at the face sides of the tubes each straddling a tube and shaped for extensive heat transmitting contact therewith, a

series of transverse backing members at the,

rear sides of the tubes, clamping means for attaching thefacing members to the backing members comprising clamping connectors eX- tending through at both sides of the tubes, and a recessed filling piece inserted between each backing member and each tube and having a projectionor flange near its upper part overlying and engaging the backing member to support the filling piece thereon.

2. A furnace wall structure comprising a system of spaced circulation tubes, a series of facing blocks at the face sides of the tubes each straddling a tube and shaped for extensive heat transmitting contact therewith, a series of transverse backing members at the rear sides of the tubes, clamping means for attaching the facing members to the backing members comprising clamping connectors extending through at both sides of the tubes, and a recessed filling piece inserted between each backing member and each tube, the backing member and filling piece having complementary engaging constructions such that the filling piece is positively supported at a definite height by the backing member.

3. A fluid cooled furnace Wall structure comprising a system of spaced circulation tubes, a series of hard cast iron facing blocks 7 at the face sides of the tubes, and shaped for extensive contact with the tubes, a series of transverse backing members behind the tubes, and clamping means connecting the blocks with the backing members, comprising threaded bolts extending through from the blocks to the backing members, between the tubes, and for each bolt a threaded nut of wrought iron preformed and embedded unitarily within and nearthe back side of a cast iron block and a back access aperture in the block substantially larger than the diameter of the bolt, and smaller than the largest diameter of the nut, whereby the bolt may be inserted, engaged with the nut and tightened against a backing member to draw each block forcibly into intimate heat conducting contact with a tube.

In testimony whereof, I have afiixed my signature hereto.

EDWARD H. TENNEY. 

